Several days of mostly quiet price action came to a fast end during U.S. trading hours Thursday afternoon, with cryptocurrencies suddenly plunging and sending bitcoin {{BTC}} to its weakest level since just after the early August market panic.

At press time, bitcoin was changing hands at $57,700, down nearly 3% from its price just about an hour earlier. Other majors saw even steeper declines, including ether {{ETH}} and solana {{SOL}}. The broad market gauge CoinDesk 20 Index was lower by 3% from 24 hours ago.

Summer 2024 has been notable for two previous panicky declines, the first of which occurred as the U.S. was enjoying its July 4 break. The catalyst for that selloff was a German government entity moving to begin selling the first of its 50,000 bitcoins which had been seized as part of a criminal probe. The second major tumble was just about two weeks ago, when what seemed like a benign rate hike by the Bank of Japan triggered a global plunge in equity markets that spread to all risk assets, crypto included.

Today's selloff, for now, appears to have no obvious catalyst. U.S. equity markets are again soaring, with the Nasdaq ahead 2.4% and the S&P 500 1.6% – both of those indices now having returned to levels seen well before the early August panic.